Methods for treating fibromyalgia syndrome

ABSTRACT

The invention is directed to a method of treating fibromyalgia syndrome in a subject, comprising administering a therapeutically effective amount of a carbamoyl compound, or pharmaceutically acceptable salt thereof.

STATEMENT OF PRIORITY

This application is a continuation of U.S. application Ser. No.13/508,145, filed Jun. 13, 2012, currently pending, which is a 35 U.S.C.§371 national phase application of PCT Application No.PCT/KR2010/007603, filed Nov. 1, 2010, which claims the benefit of U.S.Provisional Application No. 61/258,672, filed Nov. 6, 2009. The entirecontent of each of these applications is incorporated herein byreference.

TECHNICAL FIELD

The present invention relates a method of treating fibromyalgiasyndrome. More specifically, the present invention is directed to amethod of using a carbamate compound alone or in combination with othermedications, for the treatment of fibromyalgia syndrome.

BACKGROUND ART

Fibromyalgia syndrome is a chronic disease involving widespread pain,stiffness and tenderness in musculoskeletal-related tissues includingmuscles, tendons and ligaments (Bennett, 2009). Patients withfibromyalgia show sleep disturbances, fatigue, anxiety and/or fibrofog.Fibrofog encompasses the inability to concentrate, memory loss anddepression. Fibromyalgia occurs in approximately 2% of the United Statesgeneral population with a higher incidence in women (3.4%) compared tomen (0.5%) (Mease, 2005; Arnold et al., 2006).

The core symptom of fibromyalgia is the widespread pain described asarising from muscle and joints (Bennett, 2009). Many patients withfibromyalgia have tender skin. The pain typically increases anddecreases in intensity with flares accompanying unusual exertion,prolonged inactivity, soft tissue injuries, surgery, poor sleep, coldexposure, long car trips and stress. Pain is predominately axial inlocation but can also occur in hands and feet.

Fatigue is a common symptom for fibromyalgia patients. Fatigue whileused interchangeably with sleepiness has been described as a wearinessof mind and body that impairs productivity and enjoyment of life(Bennett, 2009). Treatment with antidepressants results in only a modestimprovement of fatigue suggesting that there is more to the fatiguesymptom than depression. Increased restorative sleep is not sufficientalone to reduce fatigue.

Sleep patterns are commonly disturbed in patients with fibromyalgia(Bennett, 2009). There are issues with sleep initiation and sleepmaintenance but patients feel tired when they awaken thus excessivedaytime sleepiness results in greater incompatibility with dailyfunctioning than initiation and maintenance of sleep.

Tenderness is typically reported by patients with fibromyalgia wherethere is sensitivity to touch and pain is experienced even after minorcontact (Bennett, 2009). The duration of widespread pain must be of atleast three months and tenderness must occur at 11 or more of 18specific tender spots in order to be classified as fibromyalgia (Mease,2005; Arnold et al., 2006). In addition, difficulties with memory,concentration and dual tasking are reported issues by fibromyalgiapatients.

Fibromyalgia has been shown to be comorbid with bipolar disorder, majordepressive disorder, any anxiety disorder, any eating disorder and anysubstance abuse disorder (Arnold et al, 2006). These diseases may shareunderlying pathophysiological links and treatment should be chosen withcomorbid presenting features in mind.

While the etiology of fibromyalgia is unknown, there is evidence tosuggest some abnormalities in central monoaminergic neurotransmissionincluding serotonin and norepinephrine systems (Verdu et al., 2008).Tricyclic antidepressants (TCAs) and SNRIs have been explored astreatment for fibromyalgia. TCAs including amitriptyline, andcyclobezaprine showed modest efficacy with improvements in self-ratingsof pain, stiffness, fatigue, sleep and tenderness. Limited andinconsistent results were obtained for SRIs included fluoxetine andcitalopram. Positive results were obtained for SNRIs includingduloxetine and milnacipran with better improvement in tendernesscompared to TCAs and these compounds were specifically approved forfibromyalgia treatment by the FDA in 2007 and 2009, respectively.

Antidepressants used to treat fibromyalgia show adverse reactions in asignificant percent of patients (Verdu et al., 2008). It has been shownthat progressive introduction of antidepressants increased tolerability.TCAs show mouth dryness, constipation and urinary and bowel emptyingdifficulties; effects associated with anticholinergic properties.Sedation, drowsiness and orthostatic hypotension are also common. Commonside effects of SRI are associated with the actions of serotonin andinclude nausea, gastric discomfort, vomiting, anorexia, diarrhea andskin hyperhydrosis. In addition, there is a risk of physical dependenceand withdrawal with abrupt cessation of treatment with antidepressants.Furthermore, antidepressants typically interfere with sexual functionand desire. Duloxetine was assessed for tolerability across fiveclinical trials of over 6 months in duration and the most common sideeffects included nausea, headache, dry mouth, insomnia, fatigue,constipation, diarrhea and dizziness (Choy et al., 2009) with about 20%of patients discontinuing due to adverse effects. Although milnacipranwas generally well tolerated, approximately twice as patients in thetreated groups withdrew from the study due to adverse effects includingnausea, constipation, palpitations, and flushing compared to those inthe placebo-treated group (Harris & Clauw, 2008).

Antiepileptic drugs including gabapentin and pregabalin have beenprescribed to patients with neuropathic pain subtypes and fibromyalgia(Mease, 2005). Pregabalin was the first drug approved for fibromyalgiain 2007 by the FDA. Pregabalin has demonstrated efficacy in severalrecent fibromyalgia trials with improved pain scores, quality of sleepand fatigue (Kim et al., 2009). Common side effects of pregabalinincluded dizziness, sleepiness and weight gain. Less common side effectsare difficulty concentrating and paying attention, dry mouth and blurredvision. Pregabalin is also a scheduled compound at Schedule V suggestingsome potential for abuse and withdrawal symptoms. Thus, while pregabalinshowed reduced pain in some patients, there is still room forimprovement of both efficacy and side effect profile.

Other compounds that may be useful in treating fibromyalgia includemonoamine oxidase inhibitors (i.e., pirlindole), 5-HT3 antagonists(i.e., tropisetron), opioids, tramadol, muscle relaxants, NMDA receptorantagonists and dopamine agonists (i.e., pramipexole) (Mease, 2005).Many of these compounds show either weak efficacy, less broad spectrumefficacy for symptoms or intolerable side-effect profiles included drugdependence.

DISCLOSURE OF INVENTION Technical Problem

Accordingly, there is a need in the treatment of fibromyalgia syndromethat would improve efficacy in the treatment of pain, sleep, fatigue andother comorbidities including depression and reduce side effectprofiles.

Solution to Problem

The present invention is directed to a method of treating fibromyalgiasyndrome comprising the administration of a therapeutically effectiveamount of a compound having structural Formula (1) or a pharmaceuticallyacceptable salt thereof, to a mammal in need of treatment:

wherein,

R is selected from the group consisting of hydrogen, lower alkyl of 1 to8 carbon atoms, halogen selected from F, Cl, Br and I, alkoxy of 1 to 3carbon atoms, nitro group, hydroxy, trifluoromethyl, and thioalkoxy of 1to 3 carbon atoms;

x is an integer of 1 to 3, with the proviso that R may be the same ordifferent when x is 2 or 3;

R₁ and R₂ can be the same or different from each other and areindependently selected from the group consisting of hydrogen, loweralkyl of 1 to 8 carbon atoms, aryl, arylalkyl, cycloalkyl of 3 to 7carbon atoms;

R₁ and R₂ can be joined to form a 5 to 7-membered heterocyclesubstituted with a member selected from the group consisting ofhydrogen, alkyl, and aryl groups, wherein the heterocyclic compoundcomprises 1 to 2 nitrogen atoms and 0 to 1 oxygen atom, and the nitrogenatoms are not directly connected with each other or with the oxygenatom.

In another embodiment, the present invention provides a method ofimproving symptoms associated with fibromyalgia syndrome in a subject,comprising the step of the administration, to a subject in need of suchtreatment, of a therapeutically effective amount a compound of theFormula (1) or a pharmaceutically acceptable salt thereof.

In further embodiment, the present invention provides a method ofameliorating or eliminating effects of fibromyalgia syndrome in asubject, comprising the step of the administration, to a subject in needof such treatment, of a therapeutically effective amount a compound ofthe Formula (1) or a pharmaceutically acceptable salt thereof.

In additional embodiment, the present invention is directed topharmaceutical composition for treating fibromyalgia syndrome comprisinga therapeutically effective amount a compound of the Formula (1) or apharmaceutically acceptable salt thereof.

In another embodiment, the present invention provides a pharmaceuticalcomposition for improving symptoms associated with fibromyalgia syndromein a subject, comprising a therapeutically effective amount a compoundof the Formula (1) or a pharmaceutically acceptable salt thereof.

In further embodiment, the present invention provides a pharmaceuticalcomposition for ameliorating or eliminating symptoms of fibromyalgiasyndrome in a subject, comprising a therapeutically effective amount acompound of the Formula (1) or a pharmaceutically acceptable saltthereof.

The compound having structural Formula (1) is an enantiomersubstantially free of other enantiomers or an enantiomeric mixturewherein one enantiomer of the compound having structural Formula (1)predominates. One enantiomer predominates to the extent of about 90% orgreater, and preferably about 98% or greater.

The enantiomer is (S) or (L) enantiomer as represented by StructuralFormula (1a) or (R) or (D) enantiomer, as represented by StructuralFormula (1b):

Preferably, Rx, R₁ and R₂ are all selected from hydrogen and x is 1,which are shown in the following formula:

Embodiments of the invention include a method for using the enantiomerof Formula 1 substantially free of other enantiomers that is theenantiomer of Formula 1b or an enantiomeric mixture wherein theenantiomer of Formula 1b predominates. (Note: in the structural formulaof Formula 1b below the amino group attached to the beta carbon projectsinto the plane of the paper. This is the dextrorotary (D) enantiomerthat is of absolute configuration (R))

Advantageous Effects of Invention

The present invention is based in part on the discovery thatphenylalkylamino carbamates of Formula 1 discussed above have novel andunique pharmacological properties. These compounds have been shown inseveral animal models to have the ability to treat fibromyalgia syndromeand modification of symptoms associated with fibromyalgia syndrome.

Although the precise mechanism of action is not completely understood,it is known that these compounds do not work by the same mechanisms asmost other known treatments for fibromyalgia syndrome. For thesereasons, the compounds of Formula 1 are especially suitable for use assole or adjunctive treatment for fibromyalgia and modification ofsymptoms associated with fibromyalgia syndrome.

BEST MODE FOR CARRYING OUT THE INVENTION

These and other objects of the invention will be more fully understoodfrom the following description of the invention and the claims appendedhereto.

The present invention is directed to a method of treating fibromyalgiasyndrome comprising the administration of a therapeutically effectiveamount of a compound having structural Formula (1) or enantiomers,diastereomers, racemates or mixtures thereof, or hydrates, solvates andpharmaceutically acceptable salts and amides thereof, to a mammal inneed of treatment:

wherein,

R is selected from the group consisting of hydrogen, lower alkyl of 1 to8 carbon atoms, halogen selected from F, Cl, Br and I, alkoxy of 1 to 3carbon atoms, nitro group, hydroxy, trifluoromethyl, and thioalkoxy of 1to 3 carbon atoms;

x is an integer of 1 to 3, with the proviso that R may be the same ordifferent when x is 2 or 3;

R₁ and R₂ can be the same or different from each other and areindependently selected from the group consisting of hydrogen, loweralkyl of 1 to 8 carbon atoms, aryl, arylalkyl, cycloalkyl of 3 to 7carbon atoms;

R₁ and R₂ can be joined to form a 5 to 7-membered heterocyclesubstituted with a member selected from the group consisting ofhydrogen, alkyl, and aryl groups, wherein the heterocyclic compoundcomprises 1 to 2 nitrogen atoms and 0 to 1 oxygen atom, and the nitrogenatoms are not directly connected with each other or with the oxygenatom.

The present method also includes the use of a compound selected from thegroup consisting Formula 1a or 1b, or enantiomers, diastereomers,racemates or mixtures thereof, or hydrates, solvates andpharmaceutically acceptable salts and amides thereof:

wherein Rx, R₁ and R₂ are the same as defined above.

The present method also preferably includes the use of the D (ordextrorotary) enantiomer (of absolute configuration R) selected from thegroup consisting of Formula 1 or an enantiomeric mixture thereof. In thestructural formula of Formula 1b, the amino group attached to the betacarbon projects into the plane of the paper. This is the dextrorotary(D) enantiomer that is of absolute configuration (R).

Preferably, in the Structural Formula 1, Rx, R₁ and R₂ are hydrogen andx is 1 as represented by following Structural Formula:

O-carbamoyl-(D)-phenylalaminol is also named(R)-(beta-amino-benzenepropyl) carbamate monohydrochloric acid. Forenantiomeric mixtures, wherein O-carbamoyl-(D)-phenylalaminolpredominates, preferably, to the extent of about 90% or greater, andmore preferably about 98% or greater.

The compounds of Formula 1 can be synthesized by methods known to askilled person in the art. Some reaction schemes for synthesizingcompounds of Formula (1) have been described in published; U.S. Pat.Nos. 5,705,640, 5,756,817, 5,955,499, and 6,140,532. Details of theabove reactions schemes as well as representative examples on thepreparation of specific compounds have been described in published; U.S.Pat. Nos. 5,705,640, 5,756,817, 5,955,499, 6,140,532, all incorporatedherein by reference in their entirety.

The salts of the compounds of Formula (1) can be produced by treatingthe compound with an acid (HX) in suitable solvent or by means wellknown to those of skill in the art.

From Structural Formula 1, it is evident that some of the compounds ofthe invention have at least one and possibly more asymmetric carbonatoms. It is intended that the present invention include within itsscope the stereochemically pure isomeric forms of the compounds as wellas their racemates. Stereochemically pure isomeric forms may be obtainedby the application of art known principles. Diastereoisomers may beseparated by physical separation methods such as fractionalcrystallization and chromatographic techniques, and enantiomers may beseparated from each other by the selective crystallization of thediastereomeric salts with optically active acids or bases or by chiralchromatography. Pure stereoisomers may also be prepared syntheticallyfrom appropriate stereochemically pure starting materials, or by usingstereoselective reactions.

During any of the processes for preparation of the compounds of thepresent invention, it may be necessary and/or desirable to protectsensitive or reactive groups on any of the molecules concerned. This maybe achieved by means of conventional protecting groups, such as thosedescribed in Protective Groups in Organic Chemistry, ed. J. F. W.McOmie, Plenum Press, 1973; and T. W. Greene & P. G. M. Wuts, ProtectiveGroups in Organic Synthesis, Third Edition, John Wiley & Sons, 1999. Theprotecting groups may be removed at a convenient subsequent stage usingmethods known from the art.

The present invention is based in part on the discovery thatphenylalkylamino carbamates of Formula 1 discussed above have novel andunique pharmacological properties. These compounds have been shown inseveral animal models to have the ability to treat fibromyalgia syndromeand modification of symptoms associated with fibromyalgia syndrome.

Although the precise mechanism of action is not completely understood,it is known that these compounds do not work by the same mechanisms asmost other known treatments for fibromyalgia syndrome. For thesereasons, the compounds of Formula 1 are especially suitable for use assole or adjunctive treatment for fibromyalgia and modification ofsymptoms associated with fibromyalgia syndrome.

Thus, these compounds can be safely used alone or in combination withother useful medications to provide enhanced efficacy and reduced sideeffects because smaller doses of each drug that could be used.

In one aspect, this invention relates to methods to treat subjectssuffering from fibromyalgia syndrome; the method comprising deliveringto the subject a therapeutically effective amount of one or more of thecarbamate compounds of the invention or a pharmaceutically acceptablesalt thereof and a pharmaceutically acceptable carrier, diluent orexcipient.

In another aspect, this invention also provides a method fordiminishing, inhibiting or eliminating the symptoms of fibromyalgiasyndrome including depression, sleep disturbances and fatigue in asubject suffering from fibromyalgia syndrome which comprisesadministering to the subject an effective amount of carbamate compoundsof the invention to diminish, inhibit or eliminate said symptoms.

Definitions

For convenience, certain terms employed in the specification, examples,and appended claims are collected here.

It is to be understood that this invention is not limited to theparticular methodology, protocols, animal species or genera, andreagents described, as such may vary. It is also to be understood thatthe terminology used herein is for the purpose of describing particularembodiments only, and is not intended to limit the scope of the presentinvention that will be limited only by the appended claims.

As used herein the term “subject” refers to an animal, preferably amammal, and most preferably a human both male and female, who has beenthe object of treatment, observation or experiment.

The term “therapeutically effective amount” as used herein, means thatamount of active compound or pharmaceutical agent that elicits thebiological or medicinal response in a tissue system, animal or humanthat is being sought by a researcher, veterinarian, medical doctor orother clinician, which includes alleviation of one or more of the signsor symptoms of the disease or disorder being treated.

The term “prophylactically effective amount” is intended to mean thatamount of a pharmaceutical drug that will prevent or reduce the risk ofoccurrence of the biological or medical event that is sought to beprevented of a tissue, a system, animal or human that is being sought bya researcher, veterinarian, medical doctor or other clinician.

The term “pharmaceutically acceptable salts” shall mean non-toxic saltsof the compounds employed in this invention which are generally preparedby reacting the free acid with a suitable organic or inorganic base.Examples of such salts include, but are not limited to, acetate,benzenesulfonate, benzoate, bicarbonate, bisulfate, bitartrate, borate,bromide, calcium, calcium edetate, camsylate, carbonate, chloride,clavulanate, citrate, dihydrochloride, edetate, edisylate, estolate,esylate, fumarate, gluceptate, gluconate, glutamate,glycollylarsanilate, hexylresorcinate, hydrabamine, hydrobromide,hydrochloride, hydroxynapthoate, iodide, isothionate, lactate,lactobionate, laurate, malate, maleate, mandelate, mesylate,methylbromide, methylnitrate, methylsulfate, mucate, napsylate, nitrate,oleate, oxalate, pamaote, palmitate, panthothenate,phosphate/diphosphate, polygalacturonate, potassium, salicylate, sodium,stearate, subacetate, succinate, tannate, tartrate, teoclate, tosylate,triethiodide, valerate.

Therefore, the term “a patient in need of treatment” as used herein willrefer to any subject or patient who currently has or may develop any ofthe above syndromes or disorders, including any mood disorder which canbe treated by antidepressant medication, or any other disorder in whichthe patient s present clinical condition or prognosis could benefit fromthe administration of one or more compounds of Formula (1) alone or incombination with another therapeutic intervention including but notlimited to another medication.

The term “treating” or “treatment” as used herein, refers to any indiciaof success in the prevention or amelioration of an injury, pathology orcondition of fibromyalgia syndrome and modification of symptoms offibromyalgia syndrome, including any objective or subjective parametersuch as abatement; remission; diminishing of symptoms or making theinjury, pathology, or condition more tolerable to the patient; slowingin the rate of degeneration or decline or worsening of the illness;making the final point of worsening less debilitating; or improving asubject's physical or mental well-being. The treatment or ameliorationof symptoms can be based on objective or subjective parameters;including the results of a physical examination, neurologicalexamination, and/or psychiatric evaluations. Accordingly, the term“treating” or “treatment” includes the administration of the compoundsor agents of the present invention for treatment of any form offibromyalgia syndrome in both males and females. In some instances,treatment with the compounds of the present invention will done incombination with other compounds to prevent, inhibit, or arrest theprogression of the fibromyalgia syndrome.

The term “therapeutic effect” as used herein, refers to the effectiveimprovement in or reduction of symptoms of fibromyalgia syndrome. Theterm “a therapeutically effective amount” as used herein means asufficient amount of one or more of the compounds of the invention toproduce a therapeutic effect, as defined above, in a subject or patientin need of such fibromyalgia treatment.

The terms “subject” or “patient” are used herein interchangeably and asused herein mean any mammal including but not limited to human beingsincluding a human patient or subject to which the compositions of theinvention can be administered. The term mammals include human patients,both male and female and non-human primates, as well as experimentalanimals such as rabbits, rats, and mice, and other animals.

Methods are known in the art for determining therapeutically andprophylactically effective doses for the instant pharmaceuticalcomposition. For example the compound can be employed at a daily dose inthe range of about 0.1 mg to 400 mg usually on a regimen of 1 to 2 timesper day, for an average adult human. The effective amount, however, maybe varied depending upon the particular compound used, the mode ofadministration, the strength of the preparation, the mode ofadministration, and the advancement of the disease condition. Inaddition, factors associated with the particular patient being treated;including patient age, weight, diet and time of administration, willresult in the need to adjust dosages.

The compound may be administered to a subject by any conventional routeof administration, including, but not limited to, intravenous, oral,subcutaneous, intramuscular, intradermal and parenteral. Depending onthe route of administration, compounds of Formula (1) can be constitutedinto any form. For example, forms suitable for oral administrationinclude solid forms, such as pills, gelcaps, tablets, caplets, capsules(each including immediate release, timed release and sustained releaseformulations), granules, and powders. Forms suitable for oraladministration also include liquid forms, such as solutions, syrups,elixirs, emulsions, and suspensions. In addition, forms useful forparenteral administration include sterile solutions, emulsions andsuspensions.

To prepare the pharmaceutical compositions of this invention, one ormore compounds of formula (1) or salt thereof as the active ingredientis intimately admixed with a pharmaceutical carrier according toconventional pharmaceutical compounding techniques. Carriers arenecessary and inert pharmaceutical excipients, including, but notlimited to, binders, suspending agents, lubricants, flavorings,sweeteners, preservatives, dyes, and coatings. In preparing compositionsin oral dosage form, any of the usual pharmaceutical carriers may beemployed. For example, for liquid oral preparations, suitable carriersand additives include water, glycols, oils, alcohols, flavoring agents,preservatives, coloring agents and the like; for solid oralpreparations, suitable carriers and additives include starches, sugars,diluents, granulating agents, lubricants, binders, disintegrating agentsand the like. For parenteral use, the carrier will usually comprisesterile water, though other ingredients, for example, for purposes suchas aiding solubility or for preservation, may be included. Injectablesuspensions may also be prepared, in which case appropriate liquidcarriers, suspending agents and the like may be employed.

Because of their ease in administration, tablets and capsules representthe most advantageous oral dosage unit form, in which case solidpharmaceutical carriers are obviously employed. If desired, tablets maybe sugar coated or enteric coated by standard techniques. Suppositoriesmay be prepared, in which case cocoa butter could be used as thecarrier. The tablets or pills can be coated or otherwise compounded toprovide a dosage form affording the advantage of prolonged action. Forexample, the tablet or pills can comprise an inner dosage and an outerdosage component, the latter being in the form of an envelope over theformer. The two components can be separated by an enteric layer, whichserves to resist disintegration in the stomach and permits the innercomponent to pass intact into the duodenum or to be delayed in release.A variety of material can be used for such enteric layers or coatings,such materials including a number of polymeric acids with such materialsas shellac, cetyl alcohol and cellulose acetate.

The active drug can also be administered in the form of liposomedelivery systems, such as small unilamellar vesicles, large unilamellarvesicles and multilamellar vesicles. Liposomes can be formed from avariety of phospholipids, such as cholesterol, stearylamine orphosphatidylcholines.

Active drug may also be delivered by the use of monoclonal antibodies asindividual carriers to which the compound molecules are coupled. Activedrug may also be coupled with soluble polymers as targetable drugcarriers. Such polymers can include polyvinyl-pyrrolidone, pyrancopolymer, polyhydroxypropyl-methacrylamide-phenol,polyhydroxy-ethyl-aspartamide-phenol, or polyethyleneoxide-polylysinesubstituted with palmitoyl residues. Furthermore, active drug may becoupled to a class of biodegradable polymers useful in achievingcontrolled release of a drug, for example, polylactic acid, polyglycolicacid, copolymers of polylactic and polyglycolic acid, polyepsiloncaprolactone, polyhydroxy butyric acid, polyorthoesters, polyacetals,polydihydropyrans, polycyanoacrylates and cross linked or amphipathicblock copolymers of hydrogels.

Preferably these compositions are in unit dosage forms such as tablets,pills, capsules, powders, granules, sterile parenteral solutions orsuspensions, metered aerosol or liquid sprays, drops, ampoules,auto-injector devices or suppositories, for oral parenteral, intranasal,sublingual or rectal administration, or for administration by inhalationor insufflation.

Alternatively, the composition may be presented in a form suitable foronce-weekly or once-monthly administration; for example, an insolublesalt of the active compound, such as the decanoate salt, may be adaptedto provide a depot preparation for intramuscular injection.

The pharmaceutical compositions herein will contain, per dosage unit,e.g., tablet, capsule, powder, injection, teaspoonful, suppository andthe like, an amount of the active ingredient necessary to deliver aneffective dose as described above. For example, the pharmaceuticalcompositions herein can contain, per unit dosage unit, from about 25 toabout 400 mg of the active ingredient. Preferably, the range is fromabout 50 to about 200 mg of the active ingredient.

In some embodiments of the present invention carbamate compoundssuitable for use in the practice of this invention will be administeredeither singly or concomitantly with at least one or more other compoundsor therapeutic agents. In these embodiments, the present inventionprovides methods to treat fibromyalgia syndrome and modification ofsymptoms associated with fibromyalgia syndrome in a patient. The methodincludes the step of; administering to a patient in need of treatment,an effective amount of one of the carbamate compounds disclosed hereinin combination with an effective amount of one or more other compoundsor therapeutic agents.

It is understood that substituents and substitution patterns on thecompounds of the present invention can be selected by one of ordinaryskill in the art to provide compounds that are chemically stable andthat can be readily synthesized by techniques known in the art as wellas the methods provided herein.

The present invention includes the use of isolated enantiomers ofFormula 1. In one preferred embodiment, a pharmaceutical compositioncomprising the isolated S-enantiomer of Formula 1 is used to providefibromyalgia syndrome treatment in a subject. In another preferredembodiment, a pharmaceutical composition comprising the isolatedR-enantiomer of Formula 1 is used to provide fibromyalgia syndrometreatment a subject

The present invention also includes the use of mixtures of enantiomersof Formula 1. In one aspect of the present invention, one enantiomerwill predominate. An enantiomer that predominates in the mixture is onethat is present in the mixture in an amount greater than any of theother enantiomers present in the mixture, e.g., in an amount greaterthan 50%. In one aspect, one enantiomer will predominate to the extentof 90% or to the extent of 91%, 92%, 93%, 94%, 95%, 96%, 97% or 98% orgreater. In one preferred embodiment, the enantiomer that predominatesin a composition comprising a compound of Formula 1 is the S-enantiomerof Formula 1.

The present invention provides methods of using enantiomers andenantiomeric mixtures of compounds represented by Formula 1. A carbamateenantiomer of Formula 1 contains a chiral center on the second aliphaticcarbon adjacent to the phenyl ring. An enantiomer that is isolated isone that is substantially free of the corresponding enantiomer. Thus, anisolated enantiomer refers to a compound that is separated viaseparation techniques or prepared free of the corresponding enantiomer.The term “substantially free”, as used herein, means that the compoundis made up of a significantly greater proportion of one enantiomer. Inpreferred embodiments, the compound includes at least about 90% byweight of a preferred enantiomer. In other embodiments of the invention,the compound includes at least about 99% by weight of a preferredenantiomer. Preferred enantiomers can be isolated from racemic mixturesby any method known to those skilled in the art, including highperformance liquid chromatography (HPLC) and the formation andcrystallization of chiral salts, or preferred enantiomers can beprepared by methods described herein.

Carbamate Compounds as Pharmaceuticals:

The present invention provides racemic mixtures, enantiomeric mixturesand isolated enantiomers of Formula 1 as pharmaceuticals. The carbamatecompounds are formulated as pharmaceuticals to provide anti-fibromyalgiaaction in a subject.

In general, the carbamate compounds of the present invention can beadministered as pharmaceutical compositions by any method known in theart for administering therapeutic drugs including oral, buccal, topical,systemic (e.g., transdermal, intranasal, or by suppository), orparenteral (e.g., intramuscular, subcutaneous, or intravenousinjection.) Administration of the compounds directly to the nervoussystem can include, for example, administration to intracerebral,intraventricular, intacerebroventricular, intrathecal, intracisternal,intraspinal or peri-spinal routes of administration by delivery viaintracranial or intravertebral needles or catheters with or without pumpdevices.

Compositions can take the form of tablets, pills, capsules, semisolids,powders, sustained release formulations, solutions, suspensions,emulsions, syrups, elixirs, aerosols, or any other appropriatecompositions; and comprise at least one compound of this invention incombination with at least one pharmaceutically acceptable excipient.Suitable excipients are well known to persons of ordinary skill in theart, and they, and the methods of formulating the compositions, can befound in such standard references as Alfonso A R: Remington'sPharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton Pa.,1985, the disclosure of which is incorporated herein by reference in itsentirety and for all purposes. Suitable liquid carriers, especially forinjectable solutions, include water, aqueous saline solution, aqueousdextrose solution, and glycols.

The carbamate compounds can be provided as aqueous suspensions. Aqueoussuspensions of the invention can contain a carbamate compound inadmixture with excipients suitable for the manufacture of aqueoussuspensions. Such excipients can include, for example, a suspendingagent, such as sodium carboxymethylcellulose, methylcellulose,hydroxypropylmethylcellulose, sodium alginate, polyvinylpyrrolidone, gumtragacanth and gum acacia, and dispersing or wetting agents such as anaturally occurring phosphatide (e.g., lecithin), a condensation productof an alkylene oxide with a fatty acid (e.g., polyoxyethylene stearate),a condensation product of ethylene oxide with a long chain aliphaticalcohol (e.g., heptadecaethylene oxycetanol), a condensation product ofethylene oxide with a partial ester derived from a fatty acid and ahexitol (e.g., polyoxyethylene sorbitol mono-oleate), or a condensationproduct of ethylene oxide with a partial ester derived from fatty acidand a hexitol anhydride (e.g., polyoxyethylene sorbitan mono-oleate).

The aqueous suspension can also contain one or more preservatives suchas ethyl or n-propyl p-hydroxybenzoate, one or more coloring agents, oneor more flavoring agents, and one or more sweetening agents, such assucrose, aspartame or saccharin. Formulations can be adjusted forosmolarity.

Oil suspensions for use in the present methods can be formulated bysuspending a carbamate compound in a vegetable oil, such as arachis oil,olive oil, sesame oil or coconut oil, or in a mineral oil such as liquidparaffin; or a mixture of these. The oil suspensions can contain athickening agent, such as beeswax, hard paraffin or cetyl alcohol.Sweetening agents can be added to provide a palatable oral preparation,such as glycerol, sorbitol or sucrose. These formulations can bepreserved by the addition of an antioxidant such as ascorbic acid. As anexample of an injectable oil vehicle, see Minto, J. Pharmacol. Exp.Ther. 281:93-102, 1997. The pharmaceutical formulations of the inventioncan also be in the form of oil-in-water emulsions. The oily phase can bea vegetable oil or a mineral oil, described above, or a mixture ofthese.

Suitable emulsifying agents include naturally occurring gums, such asgum acacia and gum tragacanth, naturally occurring phosphatides, such assoybean lecithin, esters or partial esters derived from fatty acids andhexitol anhydrides, such as sorbitan mono-oleate, and condensationproducts of these partial esters with ethylene oxide, such aspolyoxyethylene sorbitan mono-oleate. The emulsion can also containsweetening agents and flavoring agents, as in the formulation of syrupsand elixirs. Such formulations can also contain a demulcent, apreservative, or a coloring agent.

The compound of choice, alone or in combination with other suitablecomponents can be made into aerosol formulations (i.e., they can be“nebulized” to be administered via inhalation. Aerosol formulations canbe placed into pressurized acceptable propellants, such asdichlorodifluoromethane, propane, nitrogen, and the like.

Formulations of the present invention suitable for parenteraladministration, such as, for example, by intraarticular (in the joints),intravenous, intramuscular, intradermal, intraperitoneal, andsubcutaneous routes, can include aqueous and non-aqueous, isotonicsterile injection solutions, which can contain antioxidants, buffers,bacteriostats, and solutes that render the formulation isotonic with theblood of the intended recipient, and aqueous and non-aqueous sterilesuspensions that can include suspending agents, solubilizers, thickeningagents, stabilizers, and preservatives. Among the acceptable vehiclesand solvents that can be employed are water and Ringer's solution, anisotonic sodium chloride. In addition, sterile fixed oils canconventionally be employed as a solvent or suspending medium. For thispurpose, any bland fixed oil can be employed including synthetic mono-or diglycerides. In addition, fatty acids such as oleic acid canlikewise be used in the preparation of injectables. These solutions aresterile and generally free of undesirable matter.

Where the compounds are sufficiently soluble they can be dissolveddirectly in normal saline with or without the use of suitable organicsolvents, such as propylene glycol or polyethylene glycol. Dispersionsof the finely divided compounds can be made-up in aqueous starch orsodium carboxymethyl cellulose solution, or in suitable oil, such asarachis oil. These formulations can be sterilized by conventional,well-known sterilization techniques. The formulations can containpharmaceutically acceptable auxiliary substances as required toapproximate physiological conditions such as pH adjusting and bufferingagents, toxicity adjusting agents, e.g., sodium acetate, sodiumchloride, potassium chloride, calcium chloride, sodium lactate and thelike.

The concentration of a carbamate compound in these formulations can varywidely, and will be selected primarily based on fluid volumes,viscosities, body weight, and the like, in accordance with theparticular mode of administration selected and the patient's needs. ForIV administration, the formulation can be a sterile injectablepreparation, such as a sterile injectable aqueous or oleaginoussuspension. This suspension can be formulated according to the known artusing those suitable dispersing or wetting agents and suspending agents.The sterile injectable preparation can also be a sterile injectablesolution or suspension in a nontoxic parenterally acceptable diluents orsolvent, such as a solution of 1,3-butanediol. The formulations ofcommends can be presented in unit-dose or multi-dose sealed containers,such as ampoules and vials. Injection solutions and suspensions can beprepared from sterile powders, granules, and tablets of the kindpreviously described.

A carbamate compound suitable for use in the practice of this inventioncan be and is preferably administered orally. The amount of a compoundof the present invention in the composition can vary widely depending onthe type of composition, size of a unit dosage, kind of excipients, andother factors well known to those of ordinary skill in the art. Ingeneral, the final composition can comprise, for example, from 0.000001percent by weight (% w) to 50% w of the carbamate compound, preferably0.00001% w to 25% w, with the remainder being the excipient orexcipients.

Pharmaceutical formulations for oral administration can be formulatedusing pharmaceutically acceptable carriers well known in the art indosages suitable for oral administration. Such carriers enable thepharmaceutical formulations to be formulated in unit dosage forms astablets, pills, powder, dragees, capsules, liquids, lozenges, gels,syrups, slurries, suspensions, etc. suitable for ingestion by thepatient.

Formulations suitable for oral administration can consist of (a) liquidsolution, such as an effective amount of the pharmaceutical formulationsuspended in a diluents, such as water, saline or polyethyleneglycol(PEG) 400; (b) capsules, sachets or tablets, each containing apredetermined amount of the active ingredient, as liquids, solids,granules or gelatin; (c) suspensions in an appropriate liquid; and (d)suitable emulsions.

Pharmaceutical preparations for oral use can be obtained throughcombination of the compounds of the present invention with a solidexcipient, optionally grinding a resulting mixture, and processing themixture of granules, after adding suitable additional compounds, ifdesired, to obtain tablets or dragee cores. Suitable solid excipientsare carbohydrate or protein fillers and include, but are not limited tosugars, including lactose, sucrose, mannitol, or sorbitol; starch fromcorn, wheat, rice, potato, or other plants; cellulose such as methylcellulose, hydroxymethyl cellulose, hydroxypropylmethyl-cellulose orsodium carboxymethylcellulose; and gums including arabic and tragacanth;as well as proteins such as gelatin and collagen.

If desired, disintegrating or solubilizing agents can be added, such asthe cross-linked polyvinyl pyrrolidone, agar, alginic acid, or a saltthereof, such as sodium alginate. Tablet forms can include one or moreof lactose, sucrose, mannitol, sorbitol, calcium phosphates, cornstarch, potato starch, microcrystalline cellulose, gelatin, colloidalsilicon dioxide, talc, magnesium stearate, stearic acid, and otherexcipients, colorants, fillers, binders, diluents, buffering agents,moistening agents, preservatives, flavoring agents, dyes, disintegratingagents, and pharmaceutically compatible carriers. Lozenge forms cancomprise the active ingredient in a flavor, e.g., sucrose, as well aspastilles comprising the active ingredient in an inert base, such asgelatin and glycerin or sucrose and acacia emulsions, gels, and the likecontaining, in addition to the active ingredient, carriers known in theart.

The compounds of the present invention can also be administered in theform of suppositories for rectal administration of the drug. Theseformulations can be prepared by mixing the drug with a suitablenon-irritating excipient that is solid at ordinary temperatures butliquid at the rectal temperatures and will therefore melt in the rectumto release the drug. Such materials are cocoa butter and polyethyleneglycols.

The compounds of the present invention can also be administered byintranasal, intraocular, intravaginal, and intrarectal routes includingsuppositories, insufflation, powders and aerosol formulations (forexamples of steroid inhalants, see Rohatagi, J. Clin. Pharmacol.35:1187-1193, 1995; Tjwa, Ann. Allergy Asthma Immunol. 75:107-111,1995).

The compounds of the present invention can be delivered transdermally,by a topical route, formulated as applicator sticks, solutions,suspensions, emulsions, gels, creams, ointments, pastes, jellies,paints, powders, and aerosols.

Encapsulating materials can also be employed with the compounds of thepresent invention and the term “composition” can include the activeingredient in combination with an encapsulating material as aformulation, with or without other carriers. For example, the compoundsof the present invention can also be delivered as microspheres for slowrelease in the body. In one embodiment, microspheres can be administeredvia intradermal injection of drug (e.g., mifepristone)-containingmicrospheres, which slowly release subcutaneously (see Rao, J. BiomaterSci. Polym. Ed. 7:623-645, 1995; as biodegradable and injectable gelformulations (see, e.g., Gao, Pharm. Res. 12:857-863, 1995); or, asmicrospheres for oral administration (see, e.g., Eyles, J. Pharm.Pharmacol. 49:669-674, 1997). Both transdermal and intradermal routesafford constant delivery for weeks or months. Cachets can also be usedin the delivery of the compounds of the present invention.

In another embodiment, the compounds of the present invention can bedelivered by the use of liposomes which fuse with the cellular membraneor are endocytosed, i.e., by employing ligands attached to the liposomethat bind to surface membrane protein receptors of the cell resulting inendocytosis. By using liposomes, particularly where the liposome surfacecarries ligands specific for target cells, or are otherwisepreferentially directed to a specific organ, one can focus the deliveryof the carbamate compound into target cells in vivo. (See, e.g.,Al-Muhammed, J. Microencapsul. 13:293-306, 1996; Chonn, Cliff. Opin.Biotechnol. 6:698-708, 1995; Ostro, Am. J. Hosp. Pharm. 46:1576-1587,1989).

The pharmaceutical formulations of the invention can be provided as asalt and can be formed with many acids, including but not limited tohydrochloric, sulfuric, acetic, lactic, tartaric, malic, succinic, etc.Salts tend to be more soluble in aqueous or other protonic solvents thatare the corresponding free base forms. In other cases, the preferredpreparation can be a lyophilized powder which can contain, for example,any or all of the following: 1 mM-50 mM histidine, 0.1%-2% sucrose,2%-7% mannitol, at a pH range of 4.5 to 5.5, that is combined withbuffer prior to use.

Pharmaceutically acceptable salts refer to salts that arepharmaceutically acceptable and have the desired pharmacologicalproperties. Such salts include salts that may be formed where acidicprotons present in the compounds are capable of reacting with inorganicor organic bases. Suitable inorganic salts include those formed with thealkali metals, e.g. sodium and potassium, magnesium, calcium, andaluminum. Suitable organic salts include those formed with organic basessuch as the amine bases, e.g. ethanolamine, diethanolamine,triethanolamine, tromethamine, N methylglucamine, and the like.Pharmaceutically acceptable salts can also include acid addition saltsformed from the reaction of amine moieties in the parent compound withinorganic acids (e.g. hydrochloric and hydrobromic acids) and organicacids (e.g. acetic acid, citric acid, maleic acid, and the alkane- andarene-sulfonic acids such as methanesulfonic acid and benzenesulfonicacid). When there are two acidic groups present, a pharmaceuticallyacceptable salt may be a mono-acid-mono-salt or a di-salt; and similarlywhere there are more than two acidic groups present, some or all of suchgroups can be salified.

Compounds named in this invention can be present in unsalified form, orin salified form, and the naming of such compounds is intended toinclude both the original (unsalified) compound and its pharmaceuticallyacceptable salts. The present invention includes pharmaceuticallyacceptable salt forms of Formula (1). More than one crystal form of anenantiomer of Formula 1 can exist and as such are also included in thepresent invention.

A pharmaceutical composition of the invention can optionally contain, inaddition to a carbamate compound, at least one other therapeutic agentuseful in the treatment of fibromyalgia syndrome. For example, thecarbamate compounds of Formula 1 can be combined physically with otherfibromyalgia treatments in fixed dose combinations to simplify theiradministration.

Methods of formulating pharmaceutical compositions have been describedin numerous publications such as Pharmaceutical Dosage Forms: Tablets.Second Edition. Revised and Expanded. Volumes 1-3, edited by Liebermanet al; Pharmaceutical Dosage Forms: Parenteral Medications, Volumes 1-2,edited by Avis et al; and Pharmaceutical Dosage Forms: Disperse Systems.Volumes 1-2, edited by Lieberman et al; published by Marcel Dekker, Inc,the disclosure of which are herein incorporated by reference in theirentireties and for all purposes.

The pharmaceutical compositions are generally formulated as sterile,substantially isotonic and in full compliance with all GoodManufacturing Practice (GMP) regulations of the U.S. Food and DrugAdministration.

Dosage Regimens

The present invention provides methods of providing anti-fibromyalgiaaction in a mammal using carbamate compounds. The amount of thecarbamate compound necessary to reduce or treat fibromyalgia syndrome isdefined as a therapeutically or a pharmaceutically effective dose. Thedosage schedule and amounts effective for this use, i.e., the dosing ordosage regimen will depend on a variety of factors including the stageof the disease, the patient's physical status, age and the like. Incalculating the dosage regimen for a patient, the mode of administrationis also taken into account.

A person of ordinary skill in the art will be able without undueexperimentation, having regard to that skill and this disclosure, todetermine a therapeutically effective amount of a particular substitutedcarbamate compound for practice of this invention (see, e.g., Lieberman,Pharmaceutical Dosage Forms (Vols. 1-3, 1992); Lloyd, 1999, The art,Science and Technology of Pharmaceutical Compounding; and Pickar, 1999,Dosage Calculations). A therapeutically effective dose is also one inwhich any toxic or detrimental side effects of the active agent that isoutweighed in clinical terms by therapeutically beneficial effects. Itis to be further noted that for each particular subject, specific dosageregimens should be evaluated and adjusted over time according to theindividual need and professional judgment of the person administering orsupervising the administration of the compounds.

For treatment purposes, the compositions or compounds disclosed hereincan be administered to the subject in a single bolus delivery, viacontinuous delivery over an extended time period, or in a repeatedadministration protocol (e.g., by an hourly, daily or weekly, repeatedadministration protocol). The pharmaceutical formulations of the presentinvention can be administered, for example, one or more times daily, 3times per week, or weekly. In one embodiment of the present invention,the pharmaceutical formulations of the present invention are orallyadministered once or twice daily.

In this context, a therapeutically effective dosage of the carbamatecompounds can include repeated doses within a prolonged treatmentregimen that will yield clinically significant results to treatfibromyalgia syndrome. Determination of effective dosages in thiscontext is typically based on animal model studies followed up by humanclinical trials and is guided by determining effective dosages andadministration protocols that significantly reduce the occurrence orseverity of targeted exposure symptoms or conditions in the subject.Suitable models in this regard include, for example, murine, rat,porcine, feline, non-human primate, and other accepted animal modelsubjects known in the art. Alternatively, effective dosages can bedetermined using in vitro models (e.g., immunologic and histopathologicassays). Using such models, only ordinary calculations and adjustmentsare typically required to determine an appropriate concentration anddose to administer a therapeutically effective amount of thebiologically active agent(s) (e.g., amounts that are intranasallyeffective, transdermally effective, intravenously effective, orintramuscularly effective to elicit a desired response).

In an exemplary embodiment of the present invention, unit dosage formsof the compounds are prepared for standard administration regimens. Inthis way, the composition can be subdivided readily into smaller dosesat the physician's direction. For example, unit dosages can be made upin packeted powders, vials or ampoules and preferably in capsule ortablet form.

The active compound present in these unit dosage forms of thecomposition can be present in an amount of, for example, from about 10mg to about one gram or more, for single or multiple dailyadministration, according to the particular need of the patient. Byinitiating the treatment regimen with a minimal daily dose of about onegram, the blood levels of the carbamate compounds can be used todetermine whether a larger or smaller dose is indicated.

Effective administration of the carbamate compounds of this inventioncan be administered, for example, at an oral or parenteral dose of fromabout 0.01 mg/kg/dose to about 150 mg/kg/dose. Preferably,administration will be from about 0.1 mg/kg/dose to about 25 mg/kg/dose,more preferably from about 0.2 to about 18 mg/kg/dose. Therefore, thetherapeutically effective amount of the active ingredient contained perdosage unit as described herein can be, for example, from about 1 mg/dayto about 7000 mg/day for a subject having, for example, an averageweight of 70 kg.

The methods of this invention also provide for kits for use in providingtreatment of fibromyalgia syndrome. After a pharmaceutical compositioncomprising one or more carbamate compounds of this invention, with thepossible addition of one or more other compounds of therapeutic benefit,has been formulated in a suitable carrier, it can be placed in anappropriate container and labeled for providing fibromyalgia syndrometreatment. Additionally, another pharmaceutical comprising at least oneother therapeutic agent useful in the fibromyalgia syndrome treatmentcan be placed in the container as well and labeled for treatment of theindicated disease. Such labeling can include, for example, instructionsconcerning the amount, frequency and method of administration of eachpharmaceutical.

Although the foregoing invention has been described in detail by way ofexample for purposes of clarity of understanding, it will be apparent tothe artisan that certain changes and modifications are comprehended bythe disclosure and may be practiced without undue experimentation withinthe scope of the appended claims, which are presented by way ofillustration not limitation. The following examples are provided toillustrate specific aspects of the invention and are not meant to belimitations.

A better understanding of the present invention may be obtained in lightof the following examples that are set forth to illustrate, but are notto be construed to limit, the present invention.

Mode for the Invention EXAMPLE 1

The test compound (O-carbamoyl-(D)-phenylalaminol) administered at 30mg/kg intraperitoneally (IP) significantly increased paw withdrawallatency to a thermal stimulus in rats with sciatic nerve ligation. Thesedata suggest that the test compound shows anti-thermal hyperalgesicproperties.

(Methods)

Young adult male Sprague-Dawley rats (CD(SD)IGS, 150-200 g) wereinitially anesthetized with isoflurane in O₂ by a mask and the surgicalprocedure was performed according to the method described by Bennett andXie (1988). Briefly, the right sciatic nerves were loosely tied usingligatures. All experiments were conducted in accordance with theguidelines of the International Association for the Study of Pain. Thebehavioral tests were conducted at least 14 days postoperatively.

The test compound was dissolved in saline and administeredintraperitoneally at 30 mg/kg to animals in a volume of 3 mL/kg bodyweight.

To test for thermal hyperalgesia, the thermal response was determined bythe hindpaw withdrawal latency, using a plantar tester (UGO BASILE,Italy), and a modified method of Hargreaves et al. (1988). Rats wereallowed to acclimate within plastic enclosures on a clear glass platemaintained at room temperature. A radiant heat source (intensity 90) wascontrolled with a timer and focused onto the plantar surface of the ratright hind paw encompassing the glabrous skin. Paw withdrawal stoppedboth heat source and timer. A maximal cut-off 30 sec was used to preventtissue damage. Rats were assessed for thermal hyperalgesia predose (0hr) and at 1, 4 and 8 hours after 30 mg/kg test compound administration.

Data are expressed as mean±standard error of mean (SEM). The values ofbehavioral signs of neuropathic pain at various postoperative timepoints were compared with those of the preoperative control period by arepeated-measure One-way Analysis of Variance (followed by Dunnett'spost-hoc test). P-values less than 0.05 were considered to besignificant.

(Results)

The anti-heat hyperalgesic effects of test compound in the nerve-injuredrats are displayed in Table 1 below. The test compound, administeredintraperitoneally to rats, significantly increased the paw withdrawallatency to noxious thermal stimuli in comparison with the pre-injection(0 hr) withdrawal latency at 30 mg/kg, IP.

TABLE 1 Anti-thermal hyperalgesic effects (mean paw withdrawal latencyin seconds) of the test compound Drug Dose Time Post-Injection (mg/kg,IP) 0 hr 1 hr 4 hr 8 hr Test Compound 5.17 6.33 ± 6.06 ± 5.63 ± (30, n =6) 0.27 0.14**(22.3% 0.21*(17.2%) 0.16(8.8%) @) Data are expressed asmean paw withdrawal latency (sec) ± SEM *P < 0.05, **P < 0.01 vs. Pawwithdrawal latency (sec) at 0 hr @ % of Antagonism: [((Paw withdrawallatency (sec) at each time point/Paw withdrawal latency (sec) at 0 hr) −1)] × 100

EXAMPLE 2

The effects of the test compound (50-150 mg/kg, PO) on various sleepparameters were evaluated in 8 hypocretin cell ablated narcoleptic mice(prepororexin/ataxin-3 transgenic) and their littermate wild-type mice,and the effects were compared with those of modafinil, a referencewake-promoting compound. The test compound showed significantlyincreased bouts of wakefulness in both wild-type and narcoleptic miceand was able to normalize sleep patterns of narcoleptic mice.

(Methods)

The polygraph signal (EEG and EMG) was captured with SleepSign (KisselComtech), and the sleep stage was visually scored with 10 sec epoch forwakefulness, non-REM sleep and REM sleep. Scoring criteria are:Wakefulness is characterized by desynchronized low-amplitude, mixedfrequency (>4 Hz) EEG and high EMG activity. Rhythmic alpha (8-9 Hz)wave (with high EMG activities) may also appear. Non-REM ischaracterized by synchronized, high-amplitude, low-frequency (0.25-4 Hz)with reduced EMG activity (compared to wakefulness). EEG activity in REMsleep is similar to that in wakefulness, with desynchronized, mixedfrequency low amplitude waves. Rhythmic alpha (8-9 Hz) wave with reducedEMG activities may also appear. EEG activity during REM sleep is reducedeven further and in many cases, completely absent. Some muscle twitchingmay be apparent in the EMG trace during REM sleep.

Three drug doses of the test compound (50, 100 and 150 mg/kg PO) plusvehicle, was orally administered at ZT 2 (2 hours after light on) or ZT14 (2 hours after light off), and the effects on sleep was monitored for6 hours after the drug administration (the sleep data was collected for30 hours after the drug injection, and are available for furtheranalysis). The doses for modafinil were 50 and 200 mg/kg PO (plusvehicle), and modafinil was also administered at ZT 2 and ZT14.

If the polygraph signals of some mice were not sufficient to score thesleep stage with accuracy (especially bad EMG), data from these animalswere excluded, and the minimum of 5 animals (except for the highest doseof the test compound in wild-type mice in dark period, n=4) wereincluded for the data analysis and number of animals were indicated inthe figures.

Effects of test compound and modafinil on the amount of wake, non-REMsleep, REM sleep (cumulative seconds), number of episodes for each sleepstage during 6 hours, mean wake/sleep-bout lengths (seconds) wereanalyzed in each animal and the mean of each parameter was calculated ineach genotype. The effects of compounds on wake and sleep amounts areuseful to evaluate the wake promoting potency, and the number ofepisodes for each sleep stage and the mean wake/sleep bout length areparameters for evaluating the sleep fragmentation. Amphetamine andmodafinil, two main wake-promoting compounds currently used for thetreatment of EDS associated with various etiologies (narcolepsy,idiopathic hypersomnia and secondary EDS), are known to increase waketime and prolong wake bout length in normal and EDS conditions.

With these data analyses, the wake-promoting and therapeutic effects oftest compound in narcolepsy were evaluated, and the effects werecompared with those of modafinil. A comparison of the effects betweenhypocretin deficient and wild-type mice is very useful in determining ifthe wake-promotion of the test compound is dependent on the availabilityof hypocretins, and if there is a possible change in the sensitivity ofthe receptive mechanisms of test compound in narcoleptic mice due to thehypocretin ligand deficiency.

(Results)

Effects on Sleep During the Resting Period:

Very potent wake-promoting effects of test compound in both wild-typeand hypocretin-deficient narcoleptic mice were observed. The effectswere dose-dependent, and administrations of 50, 100, 150 mg/kg PO oftest compound induced continuous wakefulness in most wild-type andnarcoleptic mice for up to 3, 4 and 5 hours, respectively. During thisperiod, Non-REM and REM sleep were completely suppressed. There were noabnormal EEG patterns after test compound administration, and sleep thatoccurred after the prolonged wakefulness was normal by polygraphicassessments.

In contrast, the wake promoting effects of modafinil were modest, andthe wake promoting effect of 200 mg/kg of modafinil roughly correspondsto 50 mg/kg of test compound. However, modafinil did not strongly reduceREM sleep after the administration of 50 mg/kg of test compound.Furthermore, test compound potently reduced REM sleep, and thiscontrasts to the effects of modafinil.

Effects on Sleep During the Active Period:

The same experiment was repeated by administrating compounds in theactive period. During the active period, narcoleptic mice spend more insleep than wild-type mice. Wild-type animals typically stayed awake foralmost three hours after vehicle administration. Similar to the effectsobserved during the light period, test compound dose-dependentlyincreased wakefulness in both wild and narcoleptic mice. Wake-promotingeffects in wild-type mice were however, subtle during the dark perioddue to the high amount of wakefulness at the baseline, and only smalleffects were observed. In contrast, much pronounced wake-promotingeffects were observed in narcoleptic mice, and wake amounts in thesemice after 100 and 150 mg/kg test compound administration were broughtup to the levels of wild-type mice, suggesting that this compoundnormalizes the sleep/wake amount of narcoleptic mice. Similarly non-REMand REM sleep were reduced in narcoleptic mice by test compound and theamounts of non-REM and REM sleep were also brought down to the levels ofwild-type mice. Similar, but much weaker effects were also seen aftermodafinil administration in these mice. Although modafinildose-dependently increase wakefulness in narcoleptic mice, the high doseof modafinil (200 mg/kg) did not bring the wake amount to that of thewild-type baseline levels.

EXAMPLE 3

The test compound was tested for the effects on the forced swimmingtest, an animal model of depression, in both mice and rats. After singledoses of the test compound the mean duration of immobility was reducedwith an ED50 of 16.6 mg/kg PO in mice and 18.5 mg/kg PO in rats. Thetest compound was even more potent after multiple dosing in mice with anED50 of 5.5 mg/kg PO. These data suggest that the test compound showsantidepressant properties.

(Methods)

Male CD-1 mice (16-24 g) and male Wistar rats (90-125 g) were utilizedin these experiments. The test compound (10, 15 and 30 mg/kg) wasdissolved in physiological saline (0.9%) and administered orally PO in avolume of 1 mL/100 g body weight.

Mice and rats were placed in glass cylinders (1000 ml beakers; height 14cm, diameter 11.5 cm) and (4000 ml beakers; height 24.5 cm, diameter18.0 cm) respectively, containing water (25 degrees Celsius) up to aheight of 9.0 cm for mice and 19.0 for rats. Each mouse or rat wasplaced in the glass cylinder and allowed to swim for 2 minutes,following which, they were observed for a period of 4 minutes for signsof immobility. Immobility was defined as lack of movement, such asfloating in the water with little or no movement of hind legs. Durationof immobility was timed with a stopwatch and recorded. In someexperiments, mice or rats were allowed to swim for 6 or 10 minutes,respectively, one day prior to the forced swimming experiment.

In the single dose test, mice or rats were given test compound or 0.9%NaCl and placed in glass cylinders 1 hour or 4 hours post-treatment,respectively. In the multiple dose experiments, mice were dosed twice aday for 3 days and given an additional dose on Day 4. In addition, themice were placed in the glass cylinders containing water at 25 degreesCelsius and allowed to swim for six minutes on Day 3. Statisticalevaluation was performed using a computer program based on probitanalysis. Statistical significance was determined using Student's t-testat a P value of <0.05.

(Results)

The test compound, administered in a single dose, to mice reduced meanduration of immobility in a dose-dependent manner for doses of 10, 15and 30 mg/kg PO. 10 mg/kg of the test compound reduced the mean durationof immobility to 101 sec compared to 131 sec for control. Doses of 15and 30 mg/kg produced significant reductions of mean immobility timefrom 154 sec to 80 sec and from 132 sec to 30 sec, respectively. TheED50 value (50% reduction in mean immobility time) for the test compoundwas 16.6 mg/kg.

The test compound, after multiple dosing, to mice reduced mean durationof immobility in a dose-dependent manner for doses of 3, 5 and 8 mg/kgPO. At 3 mg/kg of test compound, mean duration of immobility was reducedto 63 sec from 85 sec for control. Doses of 5 and 8 mg/kg producedsignificant reductions of mean immobility time from 136 sec to 73 secand from 114 sec to 39 sec, respectively. The ED50 value for the testcompound was 5.5 mg/kg PO.

In rats, the test compound administered at 30 mg/kg significantlyreduced mean duration of immobility from 38 sec to 9 sec at 4 hourspost-treatment. Doses of test compound at 10 and 15 mg/kg also reducedduration of immobility from 74 sec to 62 sec and 65 sec to 39 sec,respectively, but these differences were not statistically significant.The ED50 was 18.5 mg/kg PO which is similar to the ED50 value in miceabove.

REFERENCES CITED

All references cited herein are incorporated herein by reference intheir entirety and for all purposes to the same extent as if eachindividual publication or patent or patent application was specificallyand individually indicated to be incorporated by reference in itsentirety for all purposes.

The discussion of references herein is intended merely to summarize theassertions made by their authors and no admission is made that anyreference constitutes prior art. Applicants reserve the right tochallenge the accuracy and pertinence of the cited references.

The present invention is not to be limited in terms of the particularembodiments described in this application, which are intended as singleillustrations of individual aspects of the invention. Many modificationsand variations of this invention can be made without departing from itsspirit and scope, as will be apparent to those skilled in the art.Functionally equivalent methods and apparatus within the scope of theinvention, in addition to those enumerated herein will be apparent tothose skilled in the art from the foregoing description. Suchmodifications and variations are intended to fall within the scope ofthe appended claims. The present invention is to be limited only by theterms of the appended claims, along with the full scope of equivalentsto which such claims are entitled.

The invention claimed is:
 1. A method of treating fibromyalgia syndrome,comprising administering a therapeutically effective amount of acompound having structural Formula (1) or a pharmaceutically acceptablesalt thereof, to a mammal suffering from fibromyalgia syndrome and inneed of treatment:

wherein, R is selected from the group consisting of hydrogen and loweralkyl of 1 to 8 carbon atoms, halogen selected from F, Cl, Br and I,alkoxy of 1 to 3 carbon atoms, nitro group, hydroxy, trifluoromethyl,and thioalkoxy of 1 to 3 carbon atoms; x is an integer of 1 to 3, withthe proviso that R may be the same or different when x is 2 or 3; R₁ andR₂ can be the same or different from each other and are independentlyselected from the group consisting of hydrogen, lower alkyl of 1 to 8carbon atoms, aryl, arylalkyl, and cycloalkyl of 3 to 7 carbon atoms; orR₁ and R₂ can be joined to form a 5 to 7-membered heterocyclesubstituted with a member selected from the group consisting ofhydrogen, alkyl, and aryl groups, wherein the heterocyclic compoundcomprises 1 to 2 nitrogen atoms and 0 to 1 oxygen atom, and the nitrogenatoms are not directly connected with each other or with the oxygenatom.
 2. The method of claim 1, wherein the compound having structuralFormula (1) is an enantiomer substantially free of other enantiomers oran enantiomeric mixture wherein one enantiomer of the compound havingstructural Formula (1) predominates.
 3. The method of claim 2, whereinone enantiomer predominates to the extent of about 90% or greater. 4.The method of claim 3, wherein one enantiomer predominates to the extentof about 98% or greater.
 5. The method of claim 2, wherein theenantiomer is (S) or (L) enantiomer as represented by Structural Formula(1a):


6. The method of claim 5, wherein one enantiomer predominates to theextent of about 90% or greater.
 7. The method of claim 6, wherein oneenantiomer predominates to the extent of about 98% or greater.
 8. Themethod of claim 2, wherein the enantiomer is (R) or (D) enantiomer, asrepresented by Structural Formula (1b):


9. The method of claim 8, wherein one enantiomer predominates to theextent of about 90% or greater.
 10. The method of claim 9, wherein oneenantiomer predominates to the extent of about 98% or greater.
 11. Themethod of claim 1, wherein R₁ and R₂ can be the same or different fromeach other and are independently selected from the group consisting ofhydrogen, lower alkyl of 1 to 8 carbon atoms, phenyl, phenyl-methylenyl,or cycloalkyl of 3 to 7 carbon atoms.